INTRODUCTION TO THE CIRCULATORY SYSTEM

Transcription

1 INTRODUCTION TO THE CIRCULATORY SYSTEM What des bld d? 5. What makes this pssible? : In rder fr there t be an efficient exchange f xygen, waste and nutrients there must be a high surface area between the bld and the cells and the diffusin membrane must be thin ( 1 cell thick) A circulatry system needs a that transprts (circulates) materials thrugh the bdy. A circulatry system needs a netwrk f in which the fluid circulates. A circulatry system needs a that pushes the fluid thrugh the tubes. Types f circulatry systems: Circulatry systems can be r clsed. Sme examples f pen systems include: Sme examples f clsed systems include: OPEN SYSTEMS Open systems d nt have bld. They cntain a fluid knwn as, which is a mixture f and. Hemlymph is circulated by ne r int a series f pen cavities r.

2 When the heart(s) relax the hemlymph flws passively back t the heart(s) thrugh pres called. Open systems are extremely. Insects increase the efficiency f this type f system because they have numerus penings in their bdies ( ) that allw the "bld" t cme int cntact with air. CLOSED SYSTEMS Fund in all vertebrates and in sme. Bld is cntained within a netwrk f and is separate frm interstitial fluid. There are fur main categries: A 3 chamber heart is cmmnly fund in. It cnsists f tw atria and a single. The right atria receives dexygenated bld frm the bdy and the left atria receives xygenated frm the skin and lungs. The ventricle has mixing f bth xygenated bld and dexygenated bld and is therefre is highly inefficient. A 4 chamber heart with a partial septum is cmmnly fund in. Sme mixing f xygenated and dexygenated bld still ccurs. Slightly mre efficient. Can supprt mre cmplex rganisms. A 4 chamber heart with a cmplete septum is cmmnly fund in mammals,, and birds. This creates tw circuits knw as the circuit and the systemic circuit. COMPONENTS OF BLOOD

3 PLASMA Plasma is made f apprximately water. It carries sme xygen, prteins, nutrients, minerals, disslved ins and vitamins. The prteins fund in plasma include: Albumin : Glbulin: transprt lipids, chlesterl and fat sluble vitamins Fibringen: ERYTHROCYTES Als knwn as RED BLOOD CELLS: carry xygen t cells and help carry carbn dixide away frm the cells. Cntain t increase the amunt f xygen that can be carried by bld. Sme prperties include: Bicncave shape 7 (μm ) in size 2 3 millin prduced per secnd Made in the bne marrw If xygen levels drp, then this signals fr ( ) erythrpietin t be prduced, which increases the number f red bld cells prduced. LEUKOCYTES Als knwn as WHITE BLOOD CELLS: they wrk as the bdy s defense against micr-rganisms, harmful, viruses and ther rganisms (fungi, parasites). They als digest ld red bld cells. They are frmed in the marrw. They are stred in the liver and the Outnumbered 700 t 1 by red bld cells. Types: Granular (cytplasmic granules): Agranular(n cytplasmic granules):

4 Engulphing is als knwn as Pus is a result f PLATELETS Small cell fragments with, and are prduced in bne marrw. Are pieces f brken ff frm a large cell in bne marrw. Pass thrugh bld vessels and rupture if they hit a rugh edge, like where there is a cut. They help clt bld (cagulatin). BLOOD CLOTTING: DISORDERS Anemia: Platelets stick t expsed fibres, until enugh accumulate t frm a temprary seal. Fibringen prteins are cnverted t lng strands f when a temprary clt is present. Fibrin creates a mesh r net like cvering that traps mre platelets and red bld cells, creating a clt. The reductin in bld xygen due t lw levels f hemglbin (which cntains irn) OR pr red bld cell prductin where these bld cells carry less hemglbin and get stuck in bld vessels easily (sickle cell anemia). Strkes: cltting that disldges frm ne area and then mves t stp the flw f bld in the brain Hemphilia: A disrder that results in pr cltting r slw cltting. Lack specific cltting factrs. BLOOD DONATION Occasinally, an individual may require a bld transfusin t treat a medical prblem. Hwever, nt all bld types are cmpatible with thers.

5 When the bdy receives cells with prtein markers/antigens that are different frm its wn, the immune system recgnizes it as a freign invader and attacks it by prducing antibdies t attach t the antigens. This causes agglutinatin: the bld cells t clump tgether blcking bld vessels and preventing circulatin and the delivery f xygen. Fr this reasn, an individual cannt receive bld with antigens different frm its wn. EX: Type A can t receive bld frm type B r type AB because the B antigens are freign. Hwever, since Type O bld, desn t have antigens, anyne can receive type O bld Type A Type B Type AB Type O Has prtein marker/ antigen A Has prtein marker/antigen B Has bth prtein marker/ antigen A and B Des nt have these prtein markers/ antigens Has antibdies fr B Has antibdies fr A Has n antibdies Has antibdies A and B 42% f ppulatin 10% f ppulatin 3% f ppulatin 45% f ppulatin Can receive Type A and O Can dnate t Type A and Type AB Can receive Type B and O Can dnate t Type B and type AB Can receive Types A, B, and O Can nly dnate t Type AB Can receive nly O Can dnate t Types A, B, AB, and O RHESUS FACTOR The secnd mst imprtant system Rh + (psitive) = have the Rhesus factr (antigen) n rbc Rh (negative) = d NOT have the Rhesus factr An individual wh is Rh can dnate t individual wh are Rh r Rh+ Hwever, and individual wh is Rh+ can nly dnate t ther Rh + (wuld cause agglutinatin in Rh- individuals) Ex: Type O+ wuldn t be able t dnate t Type AB- Type O- : universal dnr Type AB+: universal acceptr/recipient